1. Field of the Invention
The present invention relates to a wafer container and, more specifically, to a latching mechanism utilized in a wafer container to lock the door of the wafer container in an airtight status, keeping the wafer container in a particle free environment and low friction.
2. Description of Related Art
Various latching structures are disclosed for use in a wafer container to lock the door. Exemplars are seen in U.S. Pat. Nos. 5,586,585; 5,752,796; 5,988,392. These designs commonly use a rotary wheel to extend/retract latch means between the locking and unlocking position. These latching structures are simple and functional, however they cannot keep the wafer container in a particle free environment because they cannot lock the door in an airtight status. And they would easily produce the particle by the friction between the elements of the latching structures.
Further, U.S. Pat. No. 5,915,562 discloses a wafer container having an open front defined by a door receiving frame and a door sized for the door-receiving frame. The door receiving frame has slots on opposite sides and the door utilizes latching linkages and lifting linkages cooperate to extend, lift, lower and retract the latching portions from the door into and out of latch receptacles on the door receiving frame. The door may also have passive wafer cushions or active wafer engaging arms which extend inwardly toward the wafers to secure said wafers when the door is in place. The latching linkages, lifting linkages, and where desired the retaining arms are linked to rotatable cammed members in the interiors of the door. The cammed member utilizes cammed surfaces configured to first extend the latching portions in a first direction into the latching receptacles and to then move the latching portions in a second direction normal to the first direction to pull the door inwardly and to seal the door to the container portion.
The structure of the aforesaid U.S. Pat. No. 5,915,562 is complex and is still not satisfactory in function because particles tend to be produced during friction between movable members thereof.
Therefore, it is desirable to provide a latching mechanism for wafer container that eliminates the aforesaid drawbacks.